In a lot places elk are bugled at constantly by guys on ATVs. I'm of the opinion that unless you really know what you're doing, you probably don't want to bugle at all. In most places, I wouldn't bugle unless it was way before dawn or after dusk, just to make sure there are elk in the area.
If they are bugling you should be able to move in on them. More often than not, it's going to be a little guy, and any good sounding bugle may scare him off.
Ex. is correct, get a cow call to call the elk in closer. I only bugle to locate bulls most of the time. Some times you might bugle to pick a fight with a bull, then i'll rake a tree and bugle, he will either come to fight or gather his cows and split. Primo's has a nice (pack bugle) its not to big and does'nt let you sound to big either.
I agree with Ex, unless you have time to go out and learn how to do it and get away from the other hunters then the bugle is not worth that much. Now a cow call and I can't believe I am saying this but the Hoochie MaMa is one of the best out there will work quite well. I have seen spike bulls run over a half mile to me after I have used it.
If you're lucky enough to be on private land and can leave your stand up during the off season you can tie an old piece of cloth or something of the sort to your stand. I like to use an old camo bandana that I have. That way the deer get used to the movement and eventually don't bother even looking up when there is slight movement. This may just give you the time to draw your bow or raise your gun without being detected.